Vibration isolating support for looms



Oct. 17, 1967 J. T. GWINN, JR 3,347,277

VIBRATION ISOLATING SUPPORT FOR LOOMS Filed Oct. 15, 1963 2 Sheets-Sheet2 E W N 5 FIG. 6

INVENTOR.

United States Patent 3,347,277 VIBRATION ISOLATING SUPPORT FOR LOOMSJames T. Gwinn, Jr., Erie, Pa., assignor to Lord Corporation, Erie, Pa.,a corporation of Pennsylvania Filed Oct. 15, 1965, Ser. No. 496,280 9Claims. (Cl. 139-1) ABSTRACT OF THE DISCLOSURE Vibrations from loom layand picker mechanism are isolated by suspending the loom by universallyswingable tension links, preferably wire cables, which support the loomfor free rocking movement about an axis below the center of gravity sothat the vibrations originating in the loom and picker mechanism arespent in rocking the loom.

This application is a continuation in part of application Ser. No.426,224 filed Jan. 18, 1965.

Textile looms have a substantial vibration problem, principallyintroduced by the lay which packs the weft threads and by the pickermechanism which propels the shuttle. See Patent 2,187,510 and Shock andVibration Handbook, Harris and Crede, 1961 edition, McGraw- Hill, volume2, pages 32-6, 32-7. Typically, the lay (an unbalanced reciprocatingmember weighing some two to five hundred pounds) oscillates at speedsbetween one hundred and three hundred cycles per minute through a doubleamplitude of approximately six inches. The line of action of the inertiaforce due to oscillation of the lay is usually located above (sometimesbelow) the center of gravity of the loom and results in both fore andaft horizontal and vertical reaction forces at the loom feet (orattachment points to the supporting structure). In addition to thereaction forces due to the lay motion the picker mechanism of the loomgenerates lateral horizontal and vertical reaction forces. When the loomis rigidly attached to its support, the forces at the atachment pointsare directly transmitted to the support and in pracice have been thecause of extensive loom and building damage.

This invention isolates the vibration by supporting the loom forfriction free rocking about axes crosswise to the lay and pickermotions. Thus, the inertia forces of the lay and picker mechanism arecounteracted by the inertia force of the rest of the loom. The lay andpicker mechanism and loom motions are out of phase and theoreticalisolation of the lay and picker mechanism inertia force is 100% if sucha system is employed to its full effectiveness.

In a preferred form, the loom is suspended by flexible cables and theaxes are chosen so the lay and picker forces act through or near thecenters of percussion. This provides a seismic suspension which ideallyhas no dampnig or elasticity.

In operation, there is a weight or mass shift as the warp threads .aretransferred into finished cloth which is periodically removed from theloom, but this shift does not have a large effect upon the vibrationisolation.

The low frequency of the lay and picker vibrations (2 to 5 cycles persecond) make a resilient suspension impractical. Energy absorption orfriction damping structures for restraining motion of the loom transmitthe retarding forces to the building. The seismic suspensiontheoretically achieves 100% isolation and in practice has produced 7090%isolation on a Draper Model X3 loom with the lay operating at 218 cyclesper minute. The bare loom weighed 3447 lbs. and had a harness weighing118 lbs., a warp beam weighing 237 lbs. empty and 779 lbs. full, and acloth roll weight of 0-120 lbs. The maximum total weight was 4,344 lbs.with a full warp beam and In the drawing, FIG. 1 is a diagrammatic sideelevation of a loom, FIG. 2 is a diagrammatic front elevation of a loom,FIG. 3 is a side elevation of a loom suspension, FIG. 4 is a top plan ofthe portion of the loom suspension shown in FIG. 3, FIG. 5 is an endelevation of one of the front suspension elements, and FIG. 6 is a floorplan of the loom suspension.

In the drawing, the loom is diagrammatically indi cated at 1, typicallyweighs 4,000 pounds, and typically has an additional load of thread andfinished cloth. As the cloth is woven and the finished cloth removed,this additional load continually changes in magnitude and location.

The principal sourceof vibration in the loom is the lay diagrammaticallyindicated at 2 which is reciprocated fore and aft by a crank 3 at aspeed of from one hundred to three hundred strokes per minute. The layweights from 200 to 500 pounds and the shaking forces it generates aredamaging to textile buildings. Since the magnitude of these forcesincreases as the square of the speed, the effects are becoming morepronounced in modern high speed operation.

Another important source of vibration is the picker mechanismdiagrammatically indicated at 4 which is actuated alternately onopposite sides of the loom also at the speed of the crank 3. While thepicker mechanism is lighter in weight than the lay, the relatedaccelerations are greater and the resultant vibration is substantial.

To prevent the destructive effects of this vibration, the loom issupported by a structure diagrammatically shown in FIGS. 1 and 2 whichin effect utilizes the inertia of the loom to react against the lay andpicker mechanisms thereby isolating the vibration. In FIG. 1, in theregion of the four corners of the loom are two brackets 6 at the frontand two brackets 7 at the rear mounted on the building floor 8. The termfloor is used to include other supporting structure. Between the bracket6 and the front of the loom are flexible steel cables 9 applying to theloom a tension force along dotted lines 10. Between the brackets 7 andthe rear of the loom are flexible steel cables 11 applying to the loom atension force along dotted lines 12. The cables 9 and 11 support the.loom for rotation about an axis extending crosswise of the loom throughan instantaneous center of rotation 13. The cables may extend atdifferent angles depending on lay and loom translational and rotationalinertia properties and the lays location in the loom. As the layreciprocates, it exerts a fore and aft inertia force indicated by arrow15 a distance a above the loom center of gravity 14. When the force 15passes exactly through the loom center of percussion, the force 15produces only rocking motion of the loom about axis 13 and there is notransmission of the force 15 to the floor. Because of the continualchange in weight of the loom in the course of the weaving, the line ofaction of the forces 15 due to the lay cannot precisely pass through theloom center of percussion but acceptable results are obtained if thecenter of rotation 13 is chosen so that the line of action of force 15is near the center of percussion.

In FIG. 2, which is a front elevation of the loom, the cables 9 applytension forces to the loom along lines 10 which intersect at point 16and support the front end of the loom for rotation or rocking movementabout an axis transverse to the picker vibration forces indicated byarrow 17. The point 16 is usually at a different distance below thefloor 8 than the point 13. If the picker vibration 17 passes exactlythrough the loom center of percussion, none of the picker vibration istransmitted to the floor.

For perfect isolation of lay vibrations, b (the distance from the lineof action of the lay forces to the center of rotation 13) should beequal to T12 a 1+ on where a is the distance from the line of action ofthe lay forces to the loom center of gravity 14 and r is the centroidalradius of gyration of the loom.

For perfect isolation of the picker vibrations, b (the distance from theline of action 17 of the picker forces to the center of rotation 16)should equal to where a is the distance from the line of action of thepicker forces to the loom center of gravity and r is the centroidalradius of gyration of the loom.

Usually the lay and picker forces have lines of action 15 and 17 abovethe loom center of gravity 14 and the centers of rotation 13 and 15 arebelow the loom center of gravity. If either force has a line of actionbelow the loom center of gravity, then the corresponding center ofrotation would be above the loom center of gravity. For this case, thecables 9 and 11 would converge upwardly instead of downwardly asillustrated.

While the cables 9 and 11 in FIG. 1 are oriented to be primarilyeffective for the fore and aft lay vibrations, the cables also allowsidewise motion of the loom and are helpful in isolating the sidewiseinertia forces generated by the picker mechanism. Similarly, while thecables 9 in FIG. 2 are oriented to be primarily effective for isolatingsidewise vibrations of the picker mechanism, the cables also allow foreand aft motion of the loom which is effective in isolating the layvibrations. Stated differently, it is not necessary that the cables 9and 11 have the compound orientation illustrated in FIGS. 1 and 2. Someisolation of the picker vibration is obtained if the cables 9 at thefront of the loom do not converge toward the point 16 as illustrated inFIG. 2. While the orientations of FIGS. 1 and 2 are preferred, someisolation is obtained due to the flexibility of the support system usingcables 9 and 11 without the illustrated orientation. The cables 9 and 11are substantially non-stretchable in the length direction but are freeto flex in any direction crosswise to the length direction and areuniversally swingable tension links.

Because the cables 9 and 11 provide a tension support, .a high degree ofstability is obtained.

While metal wire cables are preferred for the elements 9, 11 due to thehigh strength and low internal friction or damping which provides theideal suspension for a seismic support, chains or hinged links may besubstituted for the cables. In the case of the links, the joints shouldpermit swinging lengthwise and crosswise of the loom if both the lay andpicker vibrations are to be isolated.

In FIGS. 3 to 6 is shown a mounting system for isolating the layvibration. This system has two brackets 18 at the front of the loommounted on the floor in the locations indicated at 19 in FIG. 6 and twobrackets 20 at the rear of the loom to be mounted on the floor in thelocations indicated at 21 in FIG. 6. The front and rear brackets at eachside of the loom are connected by a bar or strut 22 which positions thebrackets 13 and 2% in fixed relation to each other. The struts occupythe positions illustrated at 23 in FIG. 6. Each strut and its associatedfront and rear brackets comprise an assembly which may be cemented tothe building floor to fix their installed location. The struts resistthe longitudinal static forces from the brackets so that only the deadWeight of the loom is transmitted through the brackets to the buildingfloor.

Each of the front brackets 18 has a pair of wire cables 24 extendingbetween top and bottom plates 25 and 26. The top plate 25 is fixed tothe bracket 18. The bottom plate 26 underlies and is bolted to one ofthe front loom feet 27. The rear brackets 20 each have a pair of wirecables 28 extending between top and bottom plates 29 and 30. The topplate 29 is fixed to the bracket and the bottom plate 30 underlies andis bolted to one of the rear loom feet 31. The cables 24 have a steeperslope than the cables 28 because the center of gravity of the loom istoward the front. In order to keep the loom level, each bottom plate 30rests on the toe 32a of a stabilizer bracket 32 having knuckles 32bpivoted on pin 32c carried by the knuckle 32d at the upper end of a link32e. The bracket 32 has a seat 33 for a compression spring 34. The lowerend of the spring 34 seats in a member 35 fixed to bracket 20. The link32 slidably extends through the member 35 and the weight of the loomholds a nut 36 against the underside of the member 35. The position ofthe loom is adjusted by the nut 36 which raises and lowers the end ofthe bracket remote from the loom and thereby levels the loom.

The cables 24 and 23 lie in planes fore and aft of the loom and arefocused lengthwise of the loom in the same manner as cables 9 and 11 inFIG. 1. The effect of the cables 24 and 28 is primarily to cushion thelay forces. However, the cables do have some cushioning effect on thepicker forces because of the lateral or sidewise flexibility. The cables24 and 28 may also be focused crosswise of the loom in the same manneras the cables 9 in FIG. 2 to introduce additional cushioning of thepicker forces.

What is claimed as new is:

1. In a loom having a frame having supporting feet spaced on oppositesides of the frame at the front and rear and above and out of loadcarrying relation to a floor and having mounted thereon a warp beam,harness, cloth roll and reciprocating l-ay mechanism acting lengthwiseof the frame, said lay mechanism having a line of action fore and aft ofthe frame and to one side of the loom center of gravity, a floorsupporting bnacket associated wtih each foot, said bracket having itslower end in load carrying relation to the floor and its upper end abovethe associated foot, a universally swingable tension link in loadcarrying relation between the upper end of each bracket and theassociated foot, said links converging toward an axis crosswise of theloom and on the side of the loom center of gravity opposite the line ofaction of the lay mechanism.

2. The loom of claim 1 in which the line of action of the lay mechanismis above the loom center of gravity and the links converge fore and aftof the frame toward a center of rotation below the loom center ofgravity and between the front and rear of the frame.

3. The loom of claim 1 in which the frame has mounted thereon pickermechanism with a line of action to one side of the loom center ofgravity and crosswire of the frame and the links converge crosswise ofthe frame toward a center of rotation between the sides of the frame andon the side of the loom center of gravity opposite the line of action ofthe picker mechanism.

4. The loom of claim 1 in which the line of action of the lay mechanismpasses substantially through the center of percussion of the supportedloom.

5. In a loom having a frame having supporting feet spaced above and outof load carrying relation to a floor and on opposite sides of the frameat the front and rear and having mounted thereon a warp beam, harness,cloth roll and reciprocating lay and picker mechanism respectivelyacting lengthwise and crosswise of the frame, said lay and pickermechanism each having a line of action on one side of the loom center ofgravity, a supporting bracket associated with each foot, said brackethaving its lower end in load carrying relation to the floor and itsupper end spaced above the floor, a universally swingable tension linkin load carrying relation between the upper end of each bracket and itsassociated foot, the links at the front and back of the loom convergingto a center of rotation on the side of the loom center of gravityopposite the line of action of the lay mechanism and the links at theopposite sides of the loom converging toward a center of rotation on theside of the loom center of gravity opposite the line of action of thepicker mechanism.

6. The loom of claim 1 in which the frame has mounted thereon pickermechanism with a line of action above the loom center of gravity andcrosswise of the frame and in which the links converge fore and aft ofthe frame toward a center of rotation below the loom center of gravityand between the front and rear of the frame and also converge crosswiseof the frame toward a center of rotation between the sides of the frameand below the loom center of gravity.

7. In a loom having a frame having supporting feet spaced above and outof load carrying relation to a floor on opposite sides of the frame atthe front and rear and having mounted thereon a warp beam, harness,cloth roll and reciprocating lay and picker mechanism respectivelyacting lengthwise and crosswise of the frame and said lay and pickermechanism each having a line of action on one side of the loom center ofgravity, a floor supporting bracket associated with each foot, saidbracket having its lower end in load carrying relation to the floor andthe upper end spaced above the associated foot, a cable in load carryingrelation between the upper end of each bracket and the associated foot,the cables at the front and back of the loom converging to a center ofrotation on the side of the loom center of gravity opposite the line ofaction of the lay mechanism and the cables at the opposite sides of theloom converging toward a center of rotation on the side of the loomopposite the line of action of the picker mechanism.

8. The loom of claim 1 in which the line of action of the pickermechanism passes substantially through the center of percussion of thesupported loom.

9. The loom of claim 1 in which the links are cables.

References Cited UNITED STATES PATENTS 2,187,510 1/1940 Batchelder248-21 2,685,425 8/1954 Wallerstein 248-22 X 3,115,323 12/1963 Crandell248-20 3,160,376 12/1964 Kennedy et a1 139-1 X 3,204,911 9/1965 Lawrenceet al 248-358 3,239,207 3/1966 Camossi 248-358 X 3,282,543 11/1966Engels 248-22 FOREIGN PATENTS 546,004 6/ 1942 Great Britain. 1,272,6158/ 1961 France.

MERVIN STEIN, Primary Examiner.

J. KEE CHI, Assistant Examiner.

1. IN A LOOM HAVING A FRAME HAVING SUPPORTING FEET SPACED ON OPPOSITESIDES OF THE FRAME AT THE FRONT AND REAR AND ABOVE AND OUT OF LOADCARRYING RELATION TO A FLOOR AND HAVING MOUNTED THEREON A WARP BEAM,HARNESS, CLOTH ROLL AND RECIPROCATING LAY MECHANISM ACTING LENGTHWISE OFTHE FRAME, SAID LAY MECHANISM HAVING A LINE OF ACTION FORE AND AFT OFTHE FRAME AND TO ONE SIDE OF THE LOOM CENTER OF GRAVITY, A FLOORSUPPORTING BRACKET ASSOCIATED WITH EACH FOOT, SAID BRACKET HAVING ITSLOWER END IN LOAD CARRYING RELATION OF THE FLOOR AND ITS UPPER END ABOVETHE ASSOCIATED FOOT, A UNIVERSALLY SWINGABLE TENSION LINK IN LOADCARRYING RELATION BETWEEEN THE UPPER END OF EACH BRACKET AND THEASSOCIATED FOOT, SAID LINKS CONVERGING TOWARD AN AXIS CROSSWISE OF THELOOM AND ON THE SIDE OF THE LOOM CENTER OF GRAVITY OPPOSITE THE LINE OFACTION OF THE LAY MECHANISM.